Separator for negatively phototactic housefly larvae from chicken hen excreta

ABSTRACT

THE PUPAE CAN BE USED AS A PROTEIN SOURCE FOR GROWING CHICKS.   AN APPARATUS FOR SEPARATING NEGATIVELY PHOTOTACTIC HOUSEFLY LARVAE FOR CHICKEN HEN EXCRETA AND COLLECTING THE LARVAE TO ALLOW THEM TI PUPATE COMPRISED OF TWO COMPARTMENTS, AN UPPER ONE HAVING A SCREENED FLOOR AND A LOWER ONE HAVING A SOLID FLOOR, A SCREENED TRAY FITTED INTO THE LOWER COMPARTMENT AND A SOURCE OF WHITE LIGHT CHICKEN HEN EXCRETA IN THE UPPER COMPARTMENT IS SEEDED WITH HOUSEFLY EGGS, THE EGGS ARE ALLOWED TO HATCH AND THE LARVAE TO TUNNEL AND AERATE THE MANURE, THUS DEODORIZING AND REDUCING THE MOISTURE CONTENT OF THE MANURE BY MORE THAN 50%. THE LARVAE MIGRATE OUT OF THE MANURE AND PUPATE IN THE LOWER COMPARTMENT. WHEN DRIED AND GROUND

Feb. 13, 1973 c. c. CALVERT ETAL 3,716,371

SEPARATOR FOR-NEGATIVELY'PHOTOTACTIC HOUSE'FLY LARVAE FROM CHICKEN HENEXCRETA Filed Feb. 8, 1971 SOURCE OF WHITE UGHT, IQ G 30 7.6 28

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ATTORNEY United States PatentOffice 3,716,371 Patented Feb. 13, 1973ABSTRACT OF THE DISCLOSURE An apparatus for separating negativelyphototactic housefly larvae from chicken hen excreta and collecting thelarvae to allow them to pupate comprised of two compartments, an upperone having a screened floor and a lower one having a solid floor, ascreened tray fitted into the lower compartment and a source of whitelight. Chicken hen excreta in the upper compartment is seeded withhousefly eggs, the eggs are allowed to hatch and the larvae to tunneland aerate the manure, thus deodorizing and reducing the moisturecontent of the manure by more than 50% The larvae migrate out of themanure and pupate in the lower compartment. When dried and ground thepupae can be used as a protein source for growing chicks.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to an apparatus for separating negativelyphototactic housefly (Musca domestica L.) larvae from chicken henexcreta and for providing a chamber for the subsequent pupation of thelarvae. This invention also relates to a method of removing water andodor from chicken hen excreta and to producing a fertilizer or soilconditioner from the excreta. The invention further relates to a methodof producing a quality protein product from fly pupae.

The housefly referred to in the following specifications and claims isMusca domestica L. The life cycle of this housefly has the followingsequence: adult femaleegg larvae pupaadult fly. The average time fromegg to newly emerged adult fly is approximately 11 to 12 days attemperatures of 74 to 80 F. This invention utilized about 7 days of thelife cycle, from egg to pupa. The larvae of the housefly are negativelyphototactic, that is, the larvae are repelled by white light from anysource. Although only chicken hen excreta, fecal material from cagedlaying hens, is used in this invention, it seems feasible that theapparatus and process could be applied with equal success to excretafrom other avian species such as young growing chickens, turkeys, ducks,geese and nail. q Estimates from experts in the poultry industryindicate that the annual production of poultry excreta is between 40 and50 million tons. In addition to creating an enormous disposal problem,this amount of excreta creates odor problems and problems associatedwith air pollu tion, laws and regulations regarding the transportationof raw excreta and encroaching suburbia. Disposal of accumulated excretacan also be very costly for the poultry producer.

For many years poultry excreta has been disposed of by using it asfertilizer. At present, however, with the cities expanding into thesuburbs and more and more suburban areas being developed, odorsassociated with this means of disposal have brought problems with thesuburban residents and with motel and resort hotel owners. In addition,the fertilizer value of poultry excreta is not competitive withcommercially available chemical fertilizers. Incineration of poultryexcreta is also used as a means of disposal, but is not satisfactorybecause of cost and the resultant air pollution. Dehydration is alsoused to reduce the excreta to 25 to 30% of the original amount but thisreduced amount is still a disposal problem. In addition, wetting of thedehydrated material reproduces the original odor and disposal problem.Composting is used successfully in small operations, but would beimpossible when thousands of tons of excreta are involved. Lagoons,under or near the chicken house, are satisfactory if constructedproperly and if local environmental conditions are suitable. Inextremely cold or dry areas, lagoons are generally not satisfactory.Since most of these systems rely on anerobic bacterial digestion, odorscan be an extremely diflicult problem. Also, if the system 1s notproperly designed, water pollution can be a problem. Another method ofdisposal is anerobic digestion in sealed tanks. This method has beenused to produce methane gas for heating purposes, but costs areprohibitivei making the approach impractical for use on a large sca e.

The apparatus and process of the present invention are superior to anyapparatus or process currently in use for a number of reasons. The dailyaccumulation of poultry excreta can be processed to obtain a productthat is odorless, and since, once processed, the odor will not return,it may be used in bulk as a fertilizer or soil conditioner or it may,after additional drying, be pelletized for such use. Also, the processedmaterial may be used in any area, suburban or otherwise, withoutcreating a fly problem, because after one generation of housefly larvaehas been grown in the excreta, subsequent housefly larvae will notdevelop in it. Another reason for the superiority of this invention isthe fact that a quality protein product can be made from the houseflypupae. This product is a nutritious feed supplement for chicks andlaying hens. The housefly pupae, after drying and grinding, containabout 63% protein, and have been used successfully to replace soybeanmeal protein in the diet of growing chicks. It is estimated that thedaily excreta from 100,000 laying chickens would produce between 500 and1000 pounds of pupae. Another favorable aspect of this invention is thatthe process is completed within 7 or 8 days with odor eliminationoccurring within the first 3 days. The odor is mostly ammonia and, if sodesired, could be recovered as another byproduct of the process.

An object of this invention is to provide an apparatus having a chamberin which negatively phototactic housefly larvae can be separated fromchicken hen excreta, and having a second chamber in which the larvaepupate.

Another object is to provide an apparatus in which odor can be quicklyand efficiently removed from chicken hen excreta.

Still another object is to provide an apparatus in which chicken henexcreta can be quickly and efliciently converted to a non-odoriferousfertilizer or soil conditioner.

A still further object of this invention is to provide the poultryproducer with a means of disposing of large quantities of chicken henexcreta without polluting the environment.

Still another object is to use housefly larvae to convert poultryexcreta to a useful, nonodoriferous product, separate the larvae fromthe converted excreta, allow the larvae to pupate and then process thepupae to a quality protein product.

According to this invention the foregoing objects are accomplished by anapparatus comprised of two compartments, an upper one which has ascreened bottom and is divided into a relatively large center sectionand two narrow side sections while the lower compartment is notsectioned and has a solid bottom, a screened tray and a source of whitelight. The screened tray fits in the lower compartment which is providedwith a support means to keep the tray parallel to and at a predetermineddistance from the solid floor of the compartment. While operating, thecenter section of the upper compartment contains the chicken hen excretaand the compartment is mounted on the lower compartment. The two narrowside sections allow ammonia to escape from the lower compartment.

Referring to the drawings:

FIG. 1 is an exploded isometric view of the major components of thisapparatus.

FIG. 2 is a cross sectional view of the components assembled inoperating relationship.

The apparatus consists of two compartments, an upper one 10, and a loweror base member 12, a screened tray 14 and a source of white light 16.The upper compartment comprises side and end walls and a floor 22 madeof A5 inch mesh screen preferably of a corrosion resistant variety.Spaced inwardly from two opposite side walls 20 are a pair of parallelpartitions 24. They are held in fixed position by a plurality of spacers26. Thus the upper compartment is divided into a relatively large centerarea 28 and two narrow side portions 30 which serve as vent ducts.

The lower compartment 12 comprises side and end walls 34 having a solidfloor 36. The length and width of this compartment is identical withthat of compartment 10 so that when assembled one above the other theyare in alignment, as seen in FIG. 2. To facilitate assembly and maintainalignment corner flanges 38 may be pro vided. To support tray 14 cornermembers 39 are provided and the entire inner surfaces of compartment 12are painted black as suggested by the stippling in FIG. 1. The tray 14has side and end members 40 having outside dimensions corresponding tothe inside dimensions of compartment 12 so that it may be assembledtelescopically within compartment 12 as seen in FIG. 2. The bottom oftray 14 is 5 inch mesh screen 42 preferably made of plastic coatedfiberglass.

As shown in FIG. 2, chicken hen excreta E is placed in the center area28 of the top box to a depth of 2 /2 to 3 inches. Then newly laidhousefly (Musca domestica L.) eggs are seeded onto the excreta at a rateof 3 eggs per gram of excreta, and the assembled device is placed in aroom with a continuous overhead light source 16 and an air temperatureof 70 to 80 F. where it is kept for 7-8 days. During this time the flyeggs hatch and the larvae tunnel and aerate the excreta. By the 6th daymost of the larvae have passed through the Vs inch mesh screen to thetray below. The continuous overhead light prevents the negativelyphototactic fly larvae from moving upwards in search of a pupation site.Some particles of excreta drop through the A2 inch mesh screen 22 withthe larvae to the fiberglass screen 42. However, screen 42 issufficiently flexible to allow the larvae to wriggle through and drop tothe solid floor 36 of the lower compartment 12 to pupate while allowingvery little, if any, of the excreta to pass through.

Gas generated in the process passes upward through ducts 30 in uppercompartment 10 as indicated by arrows 44. It is mostly ammonia and maybe drawn off as an additional byproduct or vented to atmosphere.

For the purposes of demonstrating the utility of this invention, inchgalvanized hardware cloth was used for screen 22. However, othermaterials such as stainless steel can also he used. It is essential thatscreen 42 be made of a material that will allow a larva to pass through.Plastic coated fiberglass is such a material.

Feeding tests in which the fly pupae meal was substituted for soybeanmeal in a chick starting ration showed that the dried fly pupae providedprotein of sufiicient quality to support normal growth of chicks duringthe first two weeks of life.

At a seeding rate of 3 housefly eggs per gram of excreta, the odor ofthe manure was reduced to an unobjectionable level by the fourth day andby the eighth day, the manure was essentially odorless and friable andhad lost 56% of its original moisture.

We claim:

1. A process for converting chicken hen excreta to a non-odoriferousfertilizer and soil conditioner to provide a means for disposing oflarge quantities of the excreta without polluting the environment andfor preparing a quality protein feed supplement for growing chicks andother animals, comprising the steps of:

(a) providing a reaction zone and a dry collection zone beneath saidreaction zone;

(b) depositing chicken hen excreta in said reaction zone;

(c) seeding newly laid housefly (Musca domestica L.)

eggs onto the excreta;

(d) allowing the eggs to hatch to larvae;

(e) continuously exposing the top surface of the larvaecontainirigexcreta to white light, said light etfecting a separation of the larvaefrom the excreta by forcing the negatively phototactic larvae to moveaway from the light and tunnel downward through the excreta to the dryenvironment of the collection zone, thereby aerating the excreta andremoving most of the odor and more than 50% of the moisture from theexcreta, said larvae pupating in the collection zone;

(f) collecting the odorless and partially dried excreta from thereaction zone; and

(g) collecting and processing the pupae from the collection zone to aquality protein product.

2. The process of claim 1 in which the chicken hen excreta is seeded atthe rate of three eggs per gram of excreta.

3. The process of claim 1 wherein the housefly eggs are hatched at atemperature between and F.

References Cited UNITED STATES PATENTS 3,372,018 3/1968 Stocker et al71-21 1,208,199 12/1916 Pennewell 71-21 OTHER REFERENCES Chem.Abstracts, vol. 72, 1970, 12023, p. 231, Biological Digestion of Manure,by Diptera.

NORMAN YUDKOFF, Primary Examiner H. H. BERNSTEIN, Assistant Examiner US.Cl. X.R.

